Arrows and similar free flying projectiles are guided in flight by the action of vanes or "fletchings" adjacent to the rear end thereof which usually has a nock with a slot for engaging the string of a bow. It has long been known in both target and hunting archery that the guiding vane or "fletching" is of great importance in establishing the ballistic characteristics of arrow type projectiles. These ballistics include a first phase when the arrow passes the handle of the bow which may include both an arrow rest for supporting the underside of the arrow shaft and a sight window framed by a portion of the handle that may contact one side or the other of the arrow shaft depending on whether the archer is right or left handed. The second ballistic phase is the flight of the arrow through the air after it leaves the bow and the third ballistic phase is the entrance of the arrow into the target. When a plurality of arrows are aimed at the same point on a target, the third ballistic phase is reflected by the "grouping" of these arrows in the target.
During the first ballistic phase, one or more of the fletchings may hit the arrow rest or the sight window frame portions of the bow handle because of various errors in the shooting of the arrow. Such errors may occur during the return of the string to its rest position as the arrow is shot by releasing the string while engaged by the nock. The arrow at the moment of the shooting receives its energy from the limbs of the bow as transmitted by the bow string and this causes the arrow shaft to bend slightly. After rolling over the fingertips of the archer during the release, the string returns to its rest position in an S-shaped curve. As the slightly bent arrow passes above the arrow rest and through the sight window, it often happens that an arrow fletching hits the arrow rest and/or the frame portion of the bow handle forming the sight window. This contact causes a deviation of the rear or nock end of the arrow shaft and may cause the arrow to wobble during its flight. An incorrect nock position at the time of arrow release may also cause or contribute to arrow wobble during flight. A wobble in the plane of the bow is known as "porpoising" and a wobble transverse to the plane of the bow is known as "fishtailing". The mechanical qualities of arrow fletchings are of vital importance in determining how quickly arrow wobble is dampened and how large will be the final deviation of the arrow tip from the point of aim when the arrow enters the target.
Arrow fletchings presently exist in many different forms. During the early development of archery, mainly bird feathers were used, although leaves, fibers and other kinds of natural materials were utilized. During the last 30 to 40 years, various kinds of synthetic materials such as plastics have come into use for the production of a wide variety of arrow fletchings. These synthetic fletchings can be divided into two main groups. The first group comprises stiff, thin vanes made from hard, rigid plastics or the like. The second group comprises pliable, usually slightly thicker vanes made from relatively soft, flexible plastics or the like with good recovery characteristics.
The thin, stiff vanes tend to have less air resistance and give the arrow a relatively flat trajectory which is advantageous when shooting at long distances. However, arrows with these fletchings have greater wobble in flight and larger deviations in grouping when they hit the arrow rest or the sight window frame of the bow handle.
On the other hand, arrows with fletchings made from pliable plastic materials have less wobble and less deviation in grouping upon interference between a fletching and the arrow rest or sight window frame. However, because they may be somewhat thicker, these vanes tend to have a somewhat greater air resistance. The transverse cross-section of pliable plastic vanes may be tapered so as to converge outwardly in order to reduce air resistance during flight and also to reduce the flight deviations produced when a fletching hits the arrow rest or the sight window frame.
Another problem that may occur with pliable plastic fletchings is that they may develop vibrations known as "flutter" along the outer border of the vane during flight of the arrow. Flutter along outer portions of the fletchings may cause the arrow to fall short or otherwise increase grouping deviations.
Outdoor target archery is usually practiced at distances between 30 and 90 meters. The corresponding distances for indoor target archery vary between 18 and 50 meters. In order to stabilize the arrow flight more quickly at the relatively short indoor distances, target arrows are often fletched with either larger plastic vanes or larger natural feathers, such as turkey feathers, than can be used at longer distances. The distance required for stabilization of the arrow after it leaves the bow, namely, the distance traveled before wobble or oscillations of the arrow shaft can be dampened out, may be 50 meters or more with conventional fletchings.
Fletchings made from natural feathers are believed to give quicker arrow stabilization because of their larger friction against the air, and also are regarded as being more "forgiving" in that they cause less flight deviations upon contact with the arrow rest or the sight window frame than either rigid or pliable types of conventional plastic fletchings. On the other hand, natural feathers vary considerably in thickness and stiffness and do not have the uniformity of plastic fletchings in this regard. Another problem with arrow fletchings made from natural feathers is that they lack the resistance of plastic fletchings to the deteriorating effects of humidity.
For target archery or hunting archery at longer distances (greater than about 50 meters), arrows are often fletched with smaller plastic vanes having relatively little air resistance. These small size plastic vanes also reduce flight deviations caused by side winds, which is an essential consideration at long distance shooting.